Terpenes are organic compounds that are derived from the isoprene skeleton and occur in nature in particular as secondary substances present in organisms, in particular as secondary substances in plants. Terpenes are often odoriferous or flavoring substances, and can for example be obtained from plant-derived essential oils. Accordingly, terpenes and terpene derivatives are used as ingredients for products in the area of cosmetics, body care or for cleaning products, for instance as admixtures of odoriferous substances or aromas in perfumes, body lotions, shower gels, soaps, detergents or cleaning agents. Depending on the compound used, a variety of odor notes can be produced, for instance spicy, fresh, citrus-like or flowery fragrances of the corresponding products.
The corresponding starting products, which are offered by the chemical industry for admixture to the corresponding products, are often nitriles of terpenes or terpene derivatives. Examples are geranyl nitrile, which has an intense fresh, citrus-like odor, or citronellyl nitrile, which has a rose-like fragrance.
The corresponding nitriles are either isolated as natural products or are synthesized chemically from suitable precursors. Thus, the applicant's WO 2006/106141 describes the production of saturated nitriles from unsaturated nitriles as precursors. EP 0 491 127 describes the addition of unsaturated nitriles onto hexenols, obtaining modified nitriles. In both cases starting compounds are used that already comprise the nitrile group. Accordingly, methods are desirable by which precursors other than nitriles can also be used. DE 3139358 describes a process of production of odorants by chemical reaction of oximes to corresponding nitriles. In the context of this process, the necessary dehydration requires extreme reaction conditions, in particular caustic dehydrating agents and boiling temperatures.
There is therefore a demand for alternative methods for production of nitriles from oximes, in particular methods that take place under milder reaction conditions. Furthermore, there is a demand for suitable reagents for carrying out such a process.